Field of the Invention
The present invention relates to a method of manufacturing a light emitting device and more particularly to a growth substrate, a nitride semiconductor device and a method of manufacturing a light emitting device.
Discussion of the Related Art
Light emitting devices such as light emitting diodes (LEDs) are well-known semiconductor light emitting devices which convert electric current into light and have been widely used as light sources for image display of electronic devices including information technology devices together with GaP:N green LEDs, since red LEDs using GaAsP compound semiconductors were produced on a commercial scale in 1962.
A wavelength of light emitted from such LEDs depends on semiconductor materials used for manufacture of LEDs. The reason for this is that wavelength of light depends on a band-gap of a semiconductor material indicating the difference in energy between electrons of the valence band and electrons of the conduction band.
Gallium nitride (GaN) compound semiconductors attract much attention in the field for development of high-power electronic part devices including LEDs due to superior thermal stability and wide band gap (0.8˜6.2 eV).
The reason for this is that GaN combines with other element such as indium (In) or aluminum (Al), thus enabling production of semiconductor layers emitting green, blue and white light.
Characteristics of materials suitable for characteristics of certain devices can be obtained through control of wavelength of emitted light. For example, white LEDs which replace blue LEDs and incandescent lamps beneficial to optical recording are manufactured using GaN.
Based on advantages of such GaN-based materials, the GaN-based LED market is rapidly growing. Accordingly, GaN-based photoelectrical device technology has been remarkably developed since it commercially emerged in 1994.
Meanwhile, GaN-based semiconductors are more difficult to grow than other Group III-V compound semiconductors because high-quality substrates, that is, wafers containing a material such as GaN, InN or AlN are not present.
Accordingly, an LED structure is grown on a substrate having a heterostructure such as sapphire. In this case, many defects occur and affect performance of LEDs.
In particular, in the process of disassembling the substrate having a heterostructure from the LED structure, the LED structure may be damaged or yield may be deteriorated. For this reason, there is a need for a substrate structure and manufacturing method thereof which obtain a high yield.